JPH0727253Y2 - Anti-frosting device for vehicle - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a vehicle frost prevention device for preventing frost formation on a windshield while a vehicle is parked.

[Prior art]

In order to maintain a good forward visibility while driving the vehicle, the vehicle is equipped with a wiper device that wipes the windshield.This wiper device is suitable for removing raindrops, but freezes on the glass surface. It is not possible to wipe off the frost that has adhered. Therefore, it has been proposed that the frozen frost is once melted on the windshield and then wiped with a wiper, and a typical example thereof is disclosed in Japanese Patent Laid-Open No. 58-174046. In the prior art example described in the above publication, an outside air temperature sensor that operates when the outside air temperature becomes a predetermined temperature or less, a switch that is turned on by this sensor output, and a time relay that is connected to this switch are provided in the circuit of the battery and the wiper motor. When the temperature outside the vehicle falls below a predetermined temperature while the vehicle is parked, the sensor, switch, and time relay operate sequentially to intermittently drive the wiper motor, and the wiper wipe action prevents frost formation. is doing. Further, as schematically shown in FIG. 2, the windshield glass G is made of laminated glass, and a transparent thin film heating element is sandwiched between the laminated surfaces to reduce the power generated by the alternator O at the engine start. Part is controller C
It is also known that a large current is supplied to the heat generating element via the soaker to melt the frozen frost on the windshield in a short time of 2 to 4 minutes by Joule heat.

[Problems to be solved by the device]

By the way, in the case of preventing frost formation by the wiping action of the wiper as in the conventional example, there is a problem that the visibility is insufficient because the frost formation prevention range is limited to the wiper wiping region. Further, in a type in which frost is melted by a heating element sandwiched between laminated glass, a high voltage is usually applied to the heating element to obtain a predetermined current value. High-cost equipment is required. Further, if there is a defective insulation portion, there is a risk of causing an electric shock accident due to leakage caused by application of a high voltage. In addition, a large amount of current is required to melt frost even in a relatively short time, and the power consumption is 1500 watts or more in cold regions, and the capacity of the alternator and battery must be increased to cope with this. There are problems such as having to. Furthermore, even if the frosting condition is solved by energizing and heating the windshield, the amount of heat generated by melting ice or snow cannot be expected in the case of rainfall or snowfall, and battery output may be wasted. Battery measures are also a big issue. Therefore, the present invention is capable of operating at a low voltage and consuming less power, yet prevents frost formation on the entire front windshield during parking of the vehicle, and saves power when it is raining or snowing. An object of the present invention is to provide a vehicle frost prevention device.

[Means for Solving the Problems]

For this purpose, a vehicle frost prevention device according to the invention is provided with a conductive heating thin film built into a windshield, a temperature sensor for outputting an ON signal when the surface temperature of the windshield is 0 ° C or less, and a windshield. It is equipped with a humidity sensor that outputs an ON signal immediately before the outside air humidity in contact with it reaches a saturation point, and a raindrop sensor that detects rainfall and snowfall and outputs an ON signal, and both the temperature sensor and humidity sensor output an ON signal. In addition, a gate that outputs an ON signal to the switching transistor only when the condition that the raindrop sensor outputs an OFF signal is satisfied, a relay switch that turns ON when the switching transistor turns ON, and a vehicle parked in series with this relay switch. A main switch that is turned on at times is provided, and the conductive heating thin film is And a means that it has the circuit configuration to battery power through the laser switch and the main switch.

[Action]

According to the present invention employing such means, the surface temperature of the windshield becomes 0 ° C. or less under the weather condition without rain and snow, and the outside air in contact with the windshield is parked in the vehicle with the main switch turned on. Just before the water vapor reaches the saturation point, both the temperature sensor and the humidity sensor output an ON signal, and the raindrop sensor outputs an OFF signal, which turns on the relay switch and is built into the windshield. The conductive heating thin film is energized. When there is rainfall or snowfall, the raindrop sensor outputs an ON signal to turn off the relay switch, and the conduction heat generation thin film is cut off.

【Example】

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1 showing the circuit configuration of one embodiment, reference numeral 1 denotes a frost-prevention battery that is separate from a normal vehicle-mounted battery. The frost-prevention battery 1 is sandwiched between laminated glass forming a windshield 4 via a main switch 2 which is turned on when a vehicle is parked and a relay switch 3 which is connected in series with the main switch 2. A circuit is formed on the electrodes 4X and 4Y of the heating element 4A made of a conductive heating thin film. In addition, the frost prevention battery 1 includes a relay coil 11 corresponding to the relay switch 3 and the relay coil 11.
A switching transistor 12 connected in series to 11 is configured in parallel with the relay switch 3 and the heating element 4A.
The output side of the AND gate 15 is connected to the base of the. Here, a temperature sensor 13 which outputs an ON signal when the surface temperature of the windshield 4 becomes 0 ° C. or lower,
A humidity sensor 14 that outputs an ON signal immediately before the outside air humidity in contact with the windshield 4 reaches a saturation point, and a raindrop sensor 16 that detects the presence of rain or snow and outputs an ON signal are provided. The outputs of the temperature sensor 13 and the humidity sensor 14 are directly input to the AND gate 15, and only the output of the raindrop sensor 16 is input to the AND gate 15 via the inverter 17. Next, the operation of the vehicle frost prevention apparatus of this embodiment having such a configuration will be described. First, when it is unavoidable to park the vehicle for a long time under a weather condition in which windshield 4 is likely to be frosted in winter, etc., main switch 2 is turned on. Under such preparation, if the surface temperature of the windshield 4 becomes 0 ° C. or less and the humidity of the outside air in contact with the windshield 4 becomes 100% or more, which is the saturation point, and the frosting condition is satisfied. The temperature sensor 13 and the humidity sensor 14 output an ON signal to the AND gate 15. At this time, if there is no rain or snow, the raindrop sensor 16 outputs an off signal, the inverter 17 inverts this off signal and inputs it to the AND gate 15 as an ON signal, and the output from the AND gate 15 is H. The switching transistor 12 is turned on and the switching transistor 12 is turned on. Therefore, the relay coil 11 is energized and the relay switch 3 is turned on, the electric power from the frost preventing battery 1 is supplied to the heating element 4A via the electrodes 4X and 4Y, and the heat generation of the heating element 4A causes the windshield to wind. 4 is heated, and thus frost formation on the surface of the windshield 4 is prevented in advance. On the other hand, when there is rainfall or snowfall, the raindrop sensor 16 outputs an ON signal, so that the inverter 17 outputs an OFF signal to the AND gate 15. The output level of the AND gate 15 becomes L, and the switching transistor 12 is turned on. Is turned off, power supply to the heating element 4A made of a conductive heating thin film is cut off, and the windshield glass 4 is not heated.
That is, in the case of rain or snow, it is not possible to expect a large amount of heat generated by melting ice or snow in the heating element 4A made of a conductive heating thin film, so that power supply to the heating element 4A is cut off to save power. If the surface temperature of the windshield 4 is 0 ° C. or higher, or if the humidity of the outside air in contact with the windshield 4 is below the saturation point, there is no fear of frost formation. In this case, the temperature sensor When either the 13 or the humidity sensor 14 outputs an OFF signal, the output level of the AND gate 15 becomes L level and the switching transistor 12 is turned OFF, so that the heating element 4A is not energized. Further, even if the main switch 2 is turned off, the heating element 4A is not energized,
In these cases, the windshield glass 4 is not heated.

[Effect of device]

As described above, according to the present invention, the surface temperature of the windshield is 0 ° C. or less under weather conditions without rain and snow, and the water vapor in the outside air in contact with the windshield is parked while the vehicle is turned on. When frost is expected to occur just before the temperature reaches the saturation point, both the temperature sensor and humidity sensor output an ON signal, and the raindrop sensor outputs an OFF signal, turning on the relay switch and turning on the windshield. The conductive heat generating thin film built in is energized. When there is rainfall or snowfall, the raindrop sensor outputs an ON signal to turn off the relay switch, and the conduction heat generation thin film is cut off. Therefore, according to the present invention, it is possible to prevent frost from forming on the entire front windshield while the vehicle is parked, and in the case of rain or snow, it is possible to save power by not operating.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a circuit of a frost prevention device according to the present invention, and FIG. 2 is an explanatory diagram of a conventional frost prevention circuit. DESCRIPTION OF SYMBOLS 1 ... Battery for preventing frost, 2 ... Main switch, 3 ... Relay switch, 4 ... Windshield, 4A ... Heating element made of conductive heating thin film, 4X, 4Y ... Electrodes, 11 ... Coil, 12
… Switching transistor, 13… Temperature sensor, 14… Humidity sensor, 15… And gate, 16… Raindrop sensor, 17… Inverter.

Claims (1)

[Scope of utility model registration request] 1. A conductive heating thin film built in a windshield, a temperature sensor that outputs an ON signal when the surface temperature of the windshield is 0 ° C. or less, and immediately before the outside air humidity in contact with the windshield reaches a saturation point. Is equipped with a humidity sensor that outputs an ON signal and a raindrop sensor that detects rainfall and snowfall and outputs an ON signal. The temperature sensor and the humidity sensor both output an ON signal, and the raindrop sensor outputs an OFF signal. A gate that outputs an ON signal to the switching transistor only when the condition for outputting is satisfied, a relay switch that is turned ON when the switching transistor is turned ON, and a main switch that is connected in series to this relay switch and is turned ON when the vehicle is parked. The conductive heat generating thin film is provided in the relay switch and the main switch. Vehicle frost prevention device, characterized in that the circuit configuration to battery power through.